Patrick’s choice seems motivated in equal parts by the desire to reward a top staffer and loyal friend and to make a quasi-historic appointment. Cowan will be the first African-American Democrat to serve Massachusetts in the US Senate.

I say quasi-historic because Ed Brooke, a black Republican, won the seat on his own back in 1966 and was reelected in 1972. The first African-American elected to the US Senate since reconstruction, Brooke was the true pioneer when it comes to breaking racial barriers, both in the Senate and in Massachusetts.

Cowan is a smart, legally accomplished, likable guy, and his story is an inspiring one: The hard-working son of a seamstress mother who raised her children by herself after her husband died comes to Boston, graduates from Northeastern Law School, makes a career with a high-powered firm, and joins the Patrick administration as a key staffer.

And now, as a reward for his smarts, loyalty, friendship, and political service, lands a huge political plum.

Here’s my problem with the appointment: It’s very hard to argue that Cowan is the best person for the job.

After all, he has never been a legislator. Nor has he been involved in a policy-making way with the crucial concerns that will be decided, or at least debated, in Washington over the next few months.

Those will include the looming “sequestration” budget cuts, which will slash both defense and domestic spending unless a different deficit-reduction plan is hammered out. Some of that spending, such as NIH funding, is vital to this state’s hospital and medical-research sector. Entitlement reform and a possible broadening of the tax code are both on the table. A pitched battle over gun control may well be fought.

Those issues are large and complex. The Senate is small and complex. Cowan has little experience with either.

Patrick had other choices who did. One, of course, was former US Representative Barney Frank, who was about as effective a legislator as you can find. Yes, Frank can be a cranky customer, but during his three decades in Washington, he was also one of the most able members of Congress. Over time, he has proved himself adept both at issue-framing partisan combat and at striking compromises with Republicans. He was also one of the best debaters in the House.

But Frank obviously annoyed the governor’s team by making public his interest in the interim post. (As an aside, why, really, should that matter? It’s as though the Patrick administration is adopting the Mayor Menino style of politics.)

A second option might have been to ask former US Representative Martin Meehan to take a brief leave from his post as chancellor of the University of Massachusetts to serve as interim senator. Meehan proved very effective in the House during an era of Republican control.

The issue of relevant experience really hadn’t been explored during the governor’s press conference announcing his choice, so as Patrick passed me on his way back to his office, I asked him about it, noting that though Cowan was a nice guy, he really didn’t have that experience. It was a question the governor didn’t seem particularly interested in addressing.

“Oh, he’s a lot more than a nice guy,” Patrick replied. “Lot of depth, lot of wisdom, really shrewd, and he’s going to be great.”

I hope so and I certainly wish him well.

But let’s be honest: It dismisses the value of relevant experience to argue that Cowan is really best suited to battle for Massachusetts in the Senate in the pivotal months ahead.